Easy synthesis of highly nitrogen-enriched graphitic carbon with a high hydrogen storage capacity at room temperature

An easy method for synthesizing highly nitrogen-enriched graphitic carbon was developed and its hydrogen storage capacity was explored. The synthesis method uses a solution-based, stepwise condensation reaction between cyanuric chloride and melamine at low temperature (e.g., 0, 25, and 120 °C) and ambient pressure using conventional glassware without the need for an autoclave vessel. The physical and chemical structure of the synthesized highly nitrogen-enriched graphitic carbon was investigated by powder X-ray diffraction, scanning and transmission electron microscopy, selected area electron diffraction, energy dispersive spectroscopy, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoemission spectroscopy, and electron energy loss spectroscopy. The analyzes confirmed that the product has a highly crystalline nitrogen-enriched graphitic structure (d002 = 0.324 nm) with a carbon-to-nitrogen ratio of 1:1.12 (>50 atomic% nitrogen content). The material was determined to have an excellent hydrogen storage capacity of 0.34 wt% at room temperature under 100 bar in spite of its low BET surface area of only ∼10 m2/g.